During repeat operation of a circuit breaker, as well as during manufacture, the copper used in the conductor path is repeatedly heated and cooled. This heating and cooling causes the copper to become annealed. The annealing of the copper will cause it to lose some of its strength and thereby affecting the performance of the circuit breaker.
In addition, the area surrounding the stationary contact, there is repeatedly loaded from the repeated on-off operation of the circuit breaker. This repeated loading causes bending and/or deformation to the contact surface. Such deformations to the contact surface may cause an inadequate contact that may affect the circuit breaker performance.
In particular, the stationary conductors often suffer the greatest degradation. Since there is often a limited amount of space in the circuit breaker design, thicker materials are generally not used. Moreover, thicker and stronger materials cost more and add to the overall cost of manufacture.
Providing support to an un-insulated portion of the conductor path of the reverse loop will cause the same to short out and, accordingly, the circuit breaker will operate improperly.
In addition, a magnetic flux concentrator, for enhancing the electromagnetic force of the reverse loop, usually in the form of a steel block, is positioned within the reverse loop. The placement of the magnetic flux concentrator requires the implementation of at least one insulating buffer zone positioned between the magnetic flux concentrator and a portion of the reverse loop. This buffer zone prevents the short circuit of the reverse loop.
U.S. Pat. No. 5,313,180 entitled Molded Case Circuit Breaker Contact, describes a rotary circuit breaker. The above patent also describes the use of an anvil formed from a rigid metal block. The anvil is positioned in between the two strands of a current input conductor or "reverse loop" and makes contact with one of the strands to receive impact forces from the movable contact as it strikes the stationary contact positioned on the strand making contact with the anvil. In addition, the anvil in this patent also serves as a magnetic flux concentrator.